Phthalocyanine dyestuff intermediates



United States PatentO PHTHALOCYANINE DYESTUFF IN TERMEDIATES Application October 31, 1951, Serial No. 254,186

Claims priority, application Germany December 23, 1948 12 Claims. (Cl. 81)

No Drawing.

This invention relates to new intermediates of cobalt phthalocyanines.

This application is a continuation-in-part of our application Serial No. 133,693, filed December 17, 1949, entitled Dyestulf Intermediates, now abandoned.

Phthalocyanines are generally prepared by heating phthalic acid or phthalic anhydride with salts of heavy metals in the presence of certain nitrogen containing assistants, for instance, urea. Phthal-ic acid or phthalic anhydride may be substituted by certain functional derivatives thereof, such as phthalonitrile. On using phthalonitrile as starting material a nitrogen containing assistant, such as urea, can be dispensed with, the phthalocyanine complex being formed by directly heating the nitrile with the metal salt. Among the phthalocyanines, the copper complex is of the greatest importance, it being understood that numerous other heavy metal complexes such as the cobalt, nickel and iron complex have also been prepared. In all these processes the optimum temperatures for preparing the phthalccyanine complex are about 180-220 C. regardless of whether phthalic acid or phthal-ic anhydride or phthalonitrile is used as starting material and regardless of whether the copper, nickel, cobalt or iron complex is to be prepared.

As yet no intermediates between phthalic acid or phthalonitrile and the complex phthalocyanine could be determined and isolated'except iminophthalimides.

One of the objects of this invention is to provide new cobalt compounds which may be easily converted into cobalt phthalccyanines.

Another object of this invention is to provide a process for producing new intermediates of cobalt phthalocyanines.

A further object of this invention is to provide new cobalt compounds useful for dyeing or printing textile fibers.

A further object of this invention is to provide'stable printing pastes for printing textile fibers.

A still further object of this invention is to provide a method for producing cobalt phthalocyanines on textile fibers.

We have surprisingly discovered that new complex intermediate products are obtained, if in the presence of cobalt salts, phthalic acid or phthalic anhydride or derivatives thereof which are capable of forming phth alocyanines are submitted to the usual conditions resulting in the formation of phthalocyanines and 'the reac tion is stopped as soon as essential amounts of a yellowbrown reaction product have been formed, however, before essential amounts of cobalt phthalocyanine are to be observed. The process according to the present invention is carried out according to the methods generally,

its phthalocyanine-forming functional derivatives, such,

ice

as phthalic anhydride, ammonium phthalate, phthalic monoamide, phthalic diamide, phthalimide, mono imino phthalimide, o-cyano benzoic acid, o-cyanobenzamide and phthalo dinitrile come into consideration. Suitable cobalt salts are, for instance, cobalt chloride, cobalt nitrate, cobalt acetate, cobalt sulfate, the latter being advantageously used in admixture with ammonium chloride. The process of the present invention can be carried out in the presence of such high-boiling solvents as are customary for the manufacture of phthalocyanine. That is, for instance, nitrobenzene, dichloro benzene, trichloro benzene. When using the above-mentioned phthalic acid derivatives, with the exception of phthalo dinitrile, it is also necessary to add a substance yielding ammonia, such as urea, biuret, or to introduce ammonia into the reaction mixture, and catalytic quantities of the known compounds promoting phthalocyanine formation, such as for instance ammonium molybdate. The process should advantageously be carried out at somewhat lower temperatures than are customary in the manufacture of phthalocyanines. Temperatures of about to C. have proved to be most suitable. In many cases, however, simultaneous formation of some amounts of cobalt phthalocyanine cannot be prevented. In these cases, the new complex cobalt compound can be separated from the cobalt phthalocyanine owing to its better solubility. Particulars as 'to this step are given below and in the examples. If the reaction is carried out in the presence of solvents, the new complex cobalt compound is precipitated in the reaction mixture in a crystalline form and can be separated out by filtering. For removing small amounts of cobalt phthalocyanine which might have been formed, the new complex cobalt compound is worked up as described below. If the reaction is carried out without solvents the whole melt has to be worked For obtaining the new complex cobalt compounds it is of advantage to use the starting materials in molecular proportions generally employed in the production of metal phthalocyanines, because in this manner the highest yields are obtained. When employing different molecular proportions the new complex compounds are always formed, however, but in a somewhat lower yield.

Furthermore we have found that better yields of the new complex compounds with a reduced formation of cobalt phthalocyanine are obtained when carrying out the reaction in the presence of ammonium nitrate. Presumably the ammonium nitrate thus used has an oxidizing action on the cobalt phthalocyanine intermediately formed, but probably the nitrate radical also enters the new complex cobalt compounds which thereby become more stable. If it is intended to make use only of the oxidizing action of the ammonium nitrate, it is suflicient for carrying out the reaction to add about 1 mol of ammonium nitrate for 4 mols of the phthalic acid or its functional derivatives used. If also the stabilizing action of ammonium nitrate is to be utilized, it is necessary to add about /3 mol more of ammonium nitrate for 4 mols of phthalic acid or its functional derivatives. Notwithstanding that the complex cobalt compound will mostly contain besides the nitrate radical also the anion of the cobalt salt used.

Instead of ammonium nitrate also other oxidizing agents may be used. For carrying out the process technically, ammonium nitrate is however particularly suited, since melting proceeds smoothly and can also be carried out easily on a large scale.

In the above described process excessively high reaction temperatures are intentionally avoided, however, when using ammonium nitrate it is advantageous: to raise the temperature gradually, e. g. to ISO-200 C. and higher,

after the reaction is started at 16018() C. Heating is continued until the cobalt phthalocyanine simultaneously formed has disappeared and the new complex cobalt compound is obtained in a pure state. The process of the reaction can be followed under the microscope.

By using ammonium nitrate it is possible to obtain the new complex cobalt compounds in yields of about 8( 85 and to carry out the process on a technical scale without applying any particular precautionary measures. Moreover, separation of the new cobalt compounds from phthalocyanine is no longer necessary.

Of course instead of phthalic acid or its functional derivatives capable of being converted into phthalocyanines, such as phthalic anhydride, phthalonitrile, phthalimide, etc. also the corresponding substituted phthalic acids or the derivatives thereof may be used. The phthalic acids may be substituted by alk l-, aryl-, cycloalkyl-, alkoxy-, aroxy-, alkylthio-, arylthio-, halogene-, nitroetc, groups. Moreover heterocyclic o-dicarboxyiic acids or their derivatives such as pyridine dicarboxylic acid may be employed. In this case preferably ammonium nitrate is used for the production of these complex cobalt compounds.

According to analysis, the new complex compounds contain one atom of cobalt per 6 molecules of phthalonitrile, and in this respect, are fundamentally different, also as to their chemical constitution, from phthalocyanine. As to their chemical reactivity, the new complex cobalt compounds are similar to the complex cobalt salts described by Werner. The phthalonitrile molecules together with the cobalt probably form a complex cation. Depending on the conditions prevailing during reaction and during the working up, the anion is represented by hydroxyl groups or acid anions.

The proportion of hydroxyl groups is probably 2 OH per 1 atom of Co and 6 molecules of phthalonitriles. The OH groups can partly be substituted by anions. On processing with phthalic acid or phthalic anhydride the reaction product mostly consists of the hydroxyl complex, whereas on processing with phthalonitrile there is apparently obtained in the first line the complex salt with the acid of the cobalt salt which has been used as starting material. On processing with 'phthalonitrile and cobalt chloride there is obtained, for instance, a chlorine containing complex. The hydroxyl complexes may be converted into complex salts, e. g. into chlorides, sulfates or nitrates, by treating them with appropriate concentrated acids. On the other hand, most complex salts may be converted into hydroxyl complexes by treating them with alkaline agents. Such a conversion can be achieved, for instance, by a treatment with an alcoholic soda lye. In this way, there are first prepared alkaline compounds which, however, are easily hydrolyzed with water. Contrary to the deep blue cobalt phthalocyanine all variations of the new complex cobalt compounds mentioned above display a yellow to brown shade. The color of the chloride is red-brown and that of the nitrate or sulfate yellow-brown. With basic compounds, for instance primary amines, the new complexes yield orangered coloured reaction products. As further characteris tic features of the new complex cobalt compounds their high resistance to chlorinating, sulfonating or nitrating agents may be emphasized. Also in this respect, they are quite different from cobalt phthalocyanine which, like other phthalocyanines, can relatively easily be chlorinated and sulfonated and, moreover, is completely decomposed by nitric acid. The analytic figures of the hydroxyl complex are given as characteristic features of the new complex cobalt compounds Co=6.55% N=18.85%

The chlorine complex exhibits the following analytic figures Co=6.5%

From the above properties the methodscan be derived according to which the new complex cobalt conipounds can be isolated from the reaction mixtures and purified. One way is, for instance, by treating the crude product with strong alkalis, such as caustic soda solution, in the presence of alcohols, such as methanol. By this process the new complex cobalt compounds dissolve with a red-brown colouration, whereas any present cobalt phthalocyanine remains undissolved.

The hydroxyl complexes can be precipitated from this solution either by treating with water or by adding weak acids, such as glacial acetic acid. Another way resides in treating the crude product with strong acids, such as sulfuric acid or hydrochloric acid, in the presence of alcohols, such as methanol, the new complex cobalt compounds being dissolved thereby and precipitated by adding water. Under certain conditions the new complex cobalt compounds precipitate without any additions being necessary.

When using ammonium nitrate, the complex cobalt compound formed in the reaction is pure and need not be recovered, since heating is carried out until the simultaneously formed cobalt phthalocyanine has disappeared.

The complex cobalt compounds treated in the aforesaid manner with acids or bases in the presence of al cohols, after being precipitated, show an improved solubility in the organic solvents mentioned below. Therefore, they are especially suited for further application according to the present invention as described below.

We have further found that the above described complex cobalt compounds can be converted into cobalt phthalocyanine. This reaction is promoted by higher temperatures and by reducing agents. Under certain conditions higher temperatures alone or reducing agents will also sufiice to accelerate the reaction.

If the complex cobalt compounds, for instance, are heated to about 300 C. they turn deep blue with the formation of cobalt phthalocyanine, phthalonitrile being split OK at the same time. Formation of cobalt phthalocyanine is also observed on boiling the complex cobalt compounds in high-boiling solvents, such as quinoline, trichlorobenzene and nitrobenzene. Conversion of the new complex cobalt compounds into cobalt phthalocyanine is especially promoted by reducing agents. In the case of strong reducing agents, such as sodium hydrosulfite, reduction can first proceed up to the leuco-compound which by exposure to air, is converted into cobalt phthalocyanine.

The particular importance of the present invention consists in that it allows one to prepare cobalt phthalocyanine on a support and, especially, on the fiber. Up to the present, phthalocyanines have practically been used only as pigment dyestufis, and in the form of sulfonic acids, as direct dyes and for lakes. Many attempts have been made to produce phthalocyanine on the fiber in order to make use of the excellent fastness properties of the unsulfonated phthalocyanines also for textile purposes. All these attempts, however, failed up to now, owing to the high temperatures necessary for the formation of phthalocyanine from the starting materials.

Iniaccordance with the present invention, i. e. by using the aforementioned new complex cobalt compounds, the conditions for the formation of cobalt phthalocyanine can be easily regulated in such a manner that the textile fibers are not aflected in any way. For this purpose, all such modifications are suitable as allow the development of the dyestuff from the complex cobalt compounds at temperatures up to about C. For instance, well fixing printing pastes of the aforementioned complex cobalt compounds are obtained by pasting these compounds with a suitable solvent and adding the usual thickening agents, for instance, tragacanth, wheat starch, British gum or dextrin, and a reducing agent, for instance, sodium 'hydrosulfite, ferrous sulfate, titanium trichloride, stannous chloride, polyvalent alcohols, such as glycols and glycerol, pounds sugars, such as glucose, aldehyde bisulfite compounds, e. g. the addition product of sodium bisulfite to benzaldehyde. Suitable solvents are, for instance, formamide, N methyl formamimde, diethyl-formamid-e, dimethylol-formamide, glycol, diglycol, thiodiglycol, glycol monoethyl ether, glycerol, methanol dioxane, pyridine, or also mixtures of carboxylic amides or of sulfonic amides or -imides with polyvalent alcohols, for instance, mixtures of toluene sulfonamide and glycol, phthalimide and thiodiglycol, dimethylformamide and thiodiglycol. When using such reducing agents as develop their activity in an alkaline medium, like the said polyvalent alcohols or reducing sugars, strong alkaline agents, for instances, caustic alkalies, alkali metal carbonates or alkali metal sulfites, have still to be added. When printing upon artificial silk the addition of further agents may be necessary. Depending on the choice of the solvent and the reducing agent a more or less great portion of the solvent may be replaced by water. If a solvent is used that exhibits reducing properties, for instance the polyvalent alcohols, the addition of a special solvent may be dispensed with.

The dyestufi can be developed from the above printing pastes after printing by exposing the treated material to temperatures up to 120 C. or by steaming for a short time. The dyestuif development can still be accelerated by adding further reducing agents, such as hydrazine sulfate or sodium sulfite. When using such reducing agents as exhibit their reducing action in the acid pH-range, for instance the aldehyde bisulfite compounds, the formation of the dyestuif is promoted by the treatment with acid steam.

Of course, the said printing pastes can also be used for padding or dyeing textile fibers without the addition of a thickening agent and, if necessary, after further diluting with solvents or water, the development of the cobalt phthalocyanine on the fiber being accomplished in the same way as already described above.

In any case, the cobalt phthalocyanine formed is excellently fixed on the fiber. Therefore, the invention represents a valuable technical progress.

The present invention is illustrated by the following examples without being restricted thereto, the parts being by weight:

.(-A) EXAMPLES FOR THE MANUFACTURE OF COMPLEX COBALT COMPOUNDS Example 1 A mixture of: 300.0 parts of phthalic anhydride 360.0 parts of urea 72.0 parts of anhydrous cobalt chloride 0.6 part of ammonium molybdate 700.0 parts of nitrobenzene is gradually heated to 170 C. in a flask which is provided with a stirrer. While heating there is first obtained -a blue solution which turns green after half an hour. After a little while single blue crystals of the cobalt phthalocyanine are precipitated while the reaction mixture becomes olive. After heating for about 4 hours at 170 C. a yellow-brown compound crystallises out. If the temperature is kept at 170 C. for hours the reaction mixture has at last grown rather viscous. Now it is cooled down to 25 C., diluted with 700 parts of methanol and the brown crystal paste is sucked off, repeatedly washed with methanol, thereafter boiled out with diluted mineral acid, sucked off again and dried after washing.

There are obtained 250 parts of a crude product consisting for the most part of yellow-brown crystals, however, showing under the microscope also blue needles of cobalt phthalocyanine.

Example 2 Example 3 A mixture consisting of 25.0 parts of phthalimide 30.0 parts of urea 6.0 parts of anhydrous cobalt chloride 0.1 part of ammonium molybdate 60.0 parts of nitrobenzene is heated to 165-l70 C. for Shows. The reaction mixture is worked up as described in Example 1. Thus the same compound as indicated in Example 1 is obtained.

Example 4 27 parts of cobalt nitrate [Co(NOs)2.6H2O] are partly freed from crystal water by drying on the water-bath and, in a finely pulverised state, mixed with 50 parts of phthalic acid anhydride, 60 parts of urea, and 0.6 part of ammonium molybdate in parts of nitrobenzene. The mixture is heated to 170 C. for l0l2 hours while stirring and the reaction is stopped as soon as the mixture has become perfectly brown. Methanol is stirred into the mix at room temperature, and the precipitate is sucked off and washed with methanol until the draining liquor is colourless. Finally, the reaction product is boiled out in a weak mineral acid solution, sucked off, washed neutral and dried. The reaction product obtained in a good yield represents a brown powder which contains no blue crystals and is practically insoluble in ethanol, acetone, glacial acetic acid, and chlorobenzene. The solution in concentrated sulfuric acid shows a brown coloration. By contacting it with water there are precipitated brownish yel'low flakes.

Example 5 68 parts of phthalonitrile and 17.4 parts of cobalt chloride (dehydrated) are added to parts of nitrobenzene and the mixture is stirred at C. for 12 hours. Besides dark prisms of cobalt phthalocyanine there are formed during reaction very well shaped lemon yellow crystals. The reaction mixture can be filtered off after diluting with methanol. After boiling out with diluted sulfuric acid there is left a halogen containing brownish crude product which after drying dissolves in sulfuric acid with greenish. coloration. By gently heating the sulfuric acid solution there escapes hydrogen chloride. The compound is insoluble in organic solvents, such as butanol, toluene, and o-dichlorobenzene. The yellow crystals of the crude product, however, dissolve in concentrated hydrochloric acid with an orange-brown shade and can thus be separated from simultaneously prepared cobalt phthalocyanine.

Example 6 12 parts of cobalt chloride (anhydrous) and 0.2 part of ammonium molybdate are introduced into a melt of 150 parts of urea and 50 parts of phthalic anhydride, the temperature being gradually raised to 170 C. The melt soon takes a blue coloration. The troublesome foaming taking place during reaction may be moderated by adding benzamide. When the reaction is complete methanol is added while the mixture is still very hot; it is sucked off at room temperature and the residue is thoroughly washed with methanol and water. The yellow'cobalt intermediate 75 product is obtained by treating the dried grey-blue crude 7 product with methanol and sulfuric acid as described in Ex m e Example 7 A mixture of 50 parts of phthalic anhydride, 60 parts of urea, 12 parts of anhydrous cobalt chloride, 8.2 parts of ammonium nitrate and 0.1 part of ammonium molybdate is heated in 120 parts of nitrobenzene while stirrmg first for one hour to 140 C. and then to 160-170 C. until beside the blue needles of the cobalt phthalocyanine the brown-yellow crystals of the complex cobalt compound appear. The mixture is then stirred for one hour at 170 C., one hour at 180 C. and for about two to three hours at ZOO-205 C. until the blue crystals of the cobalt phthalocyanine have disappeared. The melt is then allowed to cool, diluted with methanol, the yellowbrown coarse crystals of the complex cobalt compound are sucked off, washed with methanol and water and dried. In this manner 42 parts of a cobalt phthalocyanine intermediate product are obtained which can be used directly for printing textiles.

Example 8 17 parts of phthalonitrile, 4.3 parts of anhydrous cobalt chloride, 2.8 parts of ammonium nitrate, 5.6 parts of urea and 72 parts of nitrobenzene are mixed at 170 C. while stirring. From the melt which gradually turns yellow-brown, brass-yellow prisms beside a few blue dyestuif crystals consisting of cobalt phthalocyanine separate after about one hour and a half. After heating the melt for hours to 170 C., the temperature is raised for a short while to 180-190 C. until the reaction is complete and a test portion shows a uniform microscopic picture. The melt is diluted with methanol at 80 C., the yellow-brown reaction product precipitating is sucked off and washed with methanol and water. After drying, 15.7 parts of the complex cobalt compound are obtained. The compound is scarcely soluble in methanol, ethanol, acetone or pyridine, it dissolves in a solution of methanol and caustic soda with an orange-brown coloration after standing for some time. The solution is orange-yellow in concentrated sulfuric acid. By heating in quinoline or mixtures of glycol and caustic soda solution the substance is easily converted into cobalt phthalocyanine.

The experiment may also be carried out without using urea.

Example 9 12.1 parts of diphenyl-3.4-dicarboxylic acid are converted into the anhydride by boiling for half an hour in 20 parts of nitrobenzene, and cooling to about 100 C. Then 9 parts of urea, 1.8 parts of cobalt chloride and 0.1 part of ammonium molybdate are added and the mixture is heated for one hour to 160 C. After 1.3 parts of ammonium nitrate have been added, the temperature is raised to 170 C.

During the reaction the melt turns dark brown. The reaction is complete at 190195 C. For working up, the mixture is diluted with 10 parts of nitrobenzene, methanol is carefully stirred in at room temperature, and the precipitated complex cobalt compound is sucked off. It is washed with methanol and water. The yellow-brown substance is soluble in pyridine with a brown coloration, it is also soluble in ethanol upon addition of a solution of caustic soda. When heated in aniline or aqueous solutions of sodium hydrosulfite and caustic soda, tetraphenylcobalt phthalocyanine is formed.

Example 10 A mixture of 22.7 parts of 4-bromo phthalic anhydride, 18 parts of urea, 3.6 parts of anhydrous cobalt chloride, 2.6 parts of ammonium nitrate, 0.1 part of ammonium molybdate and 40 parts of nitrobenzene is heated to 170 C. for four hours. A thick paste of blue crystals consisting of tetrabromo-cobalt phthalocyanine is obtained. The blue dyestufi crystals disappear on heating gradually to ZOO-205 C., whereby the melt turns brown. The process is interrupted when the dyestufl can no longer be observed. After cooling, the final product is recovered by diluting with methanol.

For purification the isolated crude product is extracted with dilute caustic soda solution. It yields an olive-green vat with an aqueous solution of sodium hydrosulfite and caustic soda. From the vat the blue-green tetrabromophthalocyanine precipitates on shaking out with air.

Example 11 A mixture of 15.8 parts of 4-methoxy-phthalonitrile, 17.8 parts of urea, 3.5 parts of anhydrous cobalt chloride, 2.4 parts of ammonium nitrate, 0.3 part of ammonium molybdate, and 35 parts of nitrobenzene is slowly heated to 200 C. and the melt is stirred at this temperature for a further 2 /2 hours, until the initially formed cobalt phthalocyanine has disappeared again. After cooling to 100 C. the melt is diluted with benzene, the precipitate is sucked oil and washed with benzene and igroin. The dried residue is dissolved in methanol, any undissolved impurities are filtered off and the cobalt phthalocyanine intermediate product is precipitated with Water, filtered off, washed with water and dried. 10.5 parts of a yellow product are obtained, which dissolves in methanol, pyridine or dilute acetic acid with yellow to brownish-yellow coloration, and is easily converted into 4,4',4,4"'-tetrarnethoxy-cobalt-phthalocyanine or its leuco compound with suitable reducing agents, such as sodium hydrosulfite with sodium hydroxide and the like.

The intermediate product thus obtained may be applied to the vegetable fiber by slop-padding from a dilute acetate solution and developed on the fiber by a blanc vat to form phthalocyanine.

Example 12 A mixture of 19.1 parts of 4-ethoxy4phthalimide, 17.8 parts of urea, 2.2 parts of anhydrous cobalt chloride, 3.4 parts of ammonium nitrate, 0.3 part of ammonium molybdate, and 35 parts of nitrobenzene is stirred at 170' C. for about two hours. Further processing is carried out as in Example 11. The resulting cobalt phthalocyanine intermediate product shows similar properties as the compound described in Example 11.

Example 13 In the preceding example the ethoxy-p'hthalimide is replaced by 25.8 parts of 4-phcnoxy-phthalic acid and the mixture is stirred at 160170 C. for about 3 /2 hours. The melt is cooled to 8090 C. and diluted with methanol; to completely precipitate the intermediate product a small amount of a saturated solution of ammonium nitrate is added to the melt. The precipitate is filtered off, washed with methanol and stirred with a mixture of methanol, pyridine and some sodium hydroxide, and the solution containing the intermediate product is separated from small quantities of the undissolved phthalocyanine dyestutf by filtration. The filtrate is mixed with some glacial acetic acid and water, the prepicitated intermediate product is filtered off, washed with Water and dried. The intermediate product represents a yellow-brown powder which is easily converted into 4,4',4",4'"-tetramethoxycobalt-phthalocyanine or its leuco compound in pyridine water with sodium hydrosulfite and sodium hydroxide or in acetic acid with stannous chloride.

Example 14 In Example 12, 4-ethoxy-phthalimide is replaced by 19.2 parts of 4-nitrophthalimide and the melt is heated at 160- C. for 3 /2 hours. After cooling to 8090 C. the melt is diluted with methanol, the precipitate is sucked off and washed with methanol. The crude intermediate product can be isolated from small amounts of the phthalocyanine dyestuli't as described in Example 13.

The intermediate product thus obtained readily yields the leuco compound of the green 4,4,4",4-tetramethoxycobalt-phthalocyanine with sodium hydrosulfite and sodium hydroxide.

Example 15 By replacing in Example 12 the 4-ethoxy-phthalimide by 18.1 parts of 4-chloro-phthalimide a cobalt phthalocyanine intermediate product is obtained after stirring at 180 C. for 8-9 hours. This product is precipitated by diluting the melt with benzene, and separated from small amounts of phthalocyanine dyestuff as described in the preceding examples.

The intermediate product is of dark-brown-yellow color and dissolves in concentrated sulfuric acid with an orangeyellow coloration. By adding a solution of ferrous sul fate and water, the greenish-blue 4,4',4",4'"-tetramethoxycobalt-phthalocyanine precipitates. The leuco compound of the dyestutf is for-med in pyridine water with hydrosulfite and a solution of sodium hydroxide in water.

In analogous manner, the use of 21.6 parts of 3:6-dichloro-phtha limide in the above reaction results in the formation of an intermediate product of similar properties.

( B) PURIFICATION OF THE CRUDE PRODUCTS OBTAINED ACCORDING TO EXAMPLES 1 TO 6 Example 16 150. parts of the crude product obtained as described in Example 1 or Example 2 are stirred into 800 parts by volume of methanol. At a temperature of 510 C. a solution of 45 par-ts of caustic soda 30 B. in 100 parts by volume of methanol are added drop by drop to the above solution, the yellow-brown crystals being dissolved thereby with a red-brown coloration whereas the blue portion consisting of cobalt phthalocyanine remains undissolved. As soon as the yellow-brown crystals are completely dissolved, the solution is filtered and the pure compound is precipitated from the filtrate, for instance, by adding thereto 75 parts by volume of glacial acetic acid. After sucking off and washing there are obtained yellow to brown crystals which are dried at 100 C. After adding caustic s-odasolution or concentrated bydrochloric acid the pure compound dissolves in methanol with an orange coloration.

The compound obtainable according to the foregoing, which represents the hydroxyl complex, can be converted into the chloride complex by dissolving 5 parts of the complex cobalt compound at room temperature in 20 parts by volume of concentrated hydrochloric acid and heating the solution at 60 C. for about 20 minutes. Then the solution is added to 400 parts by volume of methanol at 65 C. On cooling, the red-brown chlorine complex crystallizes out and is sucked ofi in the cold, washed with cold water and dried. The product thus obtained is free from oxygen and contains 6.5% of cobalt and 8. 6% of chlorine. It can be reacted with bases, such as hexahydroaniline and pyridine, yielding thereby very well crystallised orange-colored reaction products which are free from halogen.

The hydroxyl complex obtainable according to paragraph 1 of this example can also be converted into the nitrate. For this purpose, 5 parts of hydroxyl complex are added to 20 parts by volume of concentrated nitric acid, a temporary dissolution taking place at room temperature. After stirring for a short time, there is precipitated a substance, crystallising in fine yellow needles, which is sucked off and washed with water.

Example 1 7 100 parts of the crude product prepared as described in Example 1 are introduced While stirring into 1500 parts by volume of methanol and, subsequently, 150 parts by volume of 96% sulfuric acid are added thereto. After boiling for a short time, all is dissolved except the blue 10 crystals of the cob-altphthalocyanine. Now it is filtered in the heat and the undissolved-residue is twice washed with methanol. The pure cobalt compound is separated from the hot filtrate in fine orange crystals by adding 500 parts by volume of water. It is sucked off in the cold and the residue is repeatedly washed with water and dried. An analysis shows 6.2% of cobalt and 1 8.7% of nitrogen.

Purification is possible also by dissolving the crude pr not in 10 parts of concentrated sulfuric acid and diluting the solution with water at a temperature of at most 40 C. so that an sulfuric acid solution is obtained. The cobalt phthalocyanine precipitating is then sucked off and the filtrate is poured into ice water. When processing in this manner, the desired substance is obtained in the form of small yellow crystals. It is sucked off, washed neutral with water and dried.

If the methanol suspension of the substance is heated in the presence of caustic soda solution for a short time to the boil, fine red-brown crystals are precipitated from the brownish solution. Y

Example 18 (C) MANUFACTURE OF COBALT PHTHALO- CYANINE Example 19 20 parts of the cobalt compound obtainable according to Example 17 are heated with 62 parts of hydrazine sulfate in 600 parts by volume of glacial acetic acid on the water-bath at C. until a sample applied to paper no longer shows any colored running out, 30-45 minutes be ing required therefor. In the course of heating there is formed 'a thick reaction mix consisting of cobalt phthalocyanine which crystallizes out in the form of blue needles. It is sucked oif in the heat, repeatedly washed out with glacial acetic acid and then with water andmethanol and dried. The compound contains 104% of Co.

Formation of cobalt phthalocyanine can also be promoted by using other solvents, such as pyridine, triethanolamine, diethylaminoethanol, glycolmonoethylether, glycol etc. and reaction may also be carried out at a lower temperature. Example 20 5 parts of the yellow substance described in Example 16 are heated for some time in a salt bath at 300-320" C.

5 parts of the chloride complex obtainable according to Example 16 are slowly heated to boiling in parts by volume of quinoline. The starting material is dissolved at about C. and by further heating a large portion of the blue dyestuff prepared is precipitated in coarsecrystallized form. The latter is sucked olf at 50 C.,' washed with quinoline and methanol and dried.

Formation of the dyestufi can also be carried out by heating the chloride complex in trichlorobenzene and is particularly quickly achieved by adding piperidine.

Example 22 0.5 part of the starting material used in Example 16 is pasted with 2.5 parts by volume of phenylhydrazine. The dyestutf formation is already achieved by keeping the foregoing paste at room temperature for a short time. After diluting with methanol the dyestuff can be isolated by filtering.

5' parts of the starting material used in Example 20 are pasted with 50 parts of pyridine and this paste is added to 500 parts of water and 15 parts by volume of caustic sodasolution 30 B. On adding thereto 5 parts of sodium hydrosulfite at 3040 C. the dyestutf is precipitated and can be worked up in the usual manner. If the reaction is carried out in a more dilute solution and excess sodium hydrosulfite is used there is obtained an olive-colored vat. Other reducing agents, such as glucose and sodium formaldehyde sulfoxylate, exert a similar effect. like sodium hydrosulfite.

Example 5 parts of the starting material used in Example 19 are suspended in 60 parts by volume of ethylene glycol and 7 parts by volume of caustic soda solution B. are added thereto. On the addition of the caustic soda solution there is formed a temporary brown-red solution from which, however, after heating on the water-bath at 95-100 C., there is quickly precipitated an olive-grey paste of crystals which by further heating are converted into the blue crystals of cobalt phthalocyanine. Similar results are obtained if the cobalt complex is heated to 9540.0 C. in phenol.

Example 26 Preparation of a paste which is suitable for textile printing is described in the following: (a)- 25 parts of the pure compound obtainable according to Example 16 or Example 17 are ground in a ball mill for several hours together with 175 parts of ethylene glycol and 50 parts of caustic soda solution 32.5%, until the crystals can no longer be observed under the micro- 20 parts of a paste as described above 18 parts of glycol 13 parts of caustic soda solution (32.5%)

are gently heated thereafter stirred into 50 parts of tragacanth 1000, then mixed with 10 parts of hydrazine sulfate 4 parts of water The printing paste thus obtained is printed on cotton. Thereafter it is dried and steamed in the usual manner.

The blue dyestuif is fixed and developed by steaming for a short time. Subsequently, the textile is soaped and, if necessary, after-treated with a weak oxidizing agent. In this way, there is obtained a very clear blue printwith good fastness to rubbing, washing and boiling soda solution and with excellent fastness to light. Hydrazine sulfate can be substituted by other reducing agents, a similar effect being achieved thereby.

Example 27 This example proves that a satisfactory fixation of the dycstutf on the fiber can be achieved without using a special reducing agent. A printing paste consisting of:

150 of the paste described in Example 26(b) 60 of potash 400 of tragacanth 65/1000 50 of thiodiglycol of glycerine 240 of water 1000 parts parts parts parts parts parts partsis printed on cotton. The textile is dried and thereafter steamed for 5-10 minutes. Now the prints are rinsed and, if necessary, oxidized with hydrogen peroxide, soaped, rinsed again and dried. There are obtained bright, clear blue shades with very good fastness properties. Stability of the printing paste and of the prints before steaming is very good. Potash in the printing paste may be substituted by caustic soda or sodium sulfite.

Example 28 20 parts of the cobalt compound obtained according to Example 17 are dissolved at room temperature by adding:

20 partsof p-toluene sulfamide 100 parts of dimethyl foramide, 100-parts of glycerol,

20 parts of caustic soda solution 32.5%. The yellowbrown solution obtained is introduced with stirring into 500 parts of. tragacanth 65/1000. To the mixture are added 150 parts of formamide, 45 parts of potassium carbonate, 15 parts of glucose, 30 parts of water.

The printing paste thus obtained is printed upon cotton and the print is dried at about 60 C. Fixation and development of the dyestulf is effected either by steaming for 5 minutes in the Mather & Platt ager, or by heating for a short time to about C. By soaping at the boil a full shade blue print is obtained.

When replacing the glucose by the same quantity of a benzaldehyde bisulfite compound, developing of the dyestulf can also be effected by acid steaming.

Example 29 20 parts of the cobalt compound obtained according to Examples 6 or 16 are dissolved in a mixture of:

200 parts of diglycol, 70 parts of ethylene glycol 21 parts of triethanol amine withstirring at room temperature. The solution obtained is added to 600 parts of tragacanth 65/1000. Furthermore 50 parts of diethyl tartrate 15 parts of benzaldehyde bisulfite compound 24 parts of water 1000 parts are added This printing paste is printed on the fiber and dried as indicated in Example 28. By subsequent steaming, for 5 minutes in acid steam the intermediate product is developed to form the dyestuff. After rinsing and soaping a full shade, blue print is obtained.

We claim:

1. New complex cobalt compounds containing 6 mole cules of phthalonitrile per atom of cobalt, capable of being converted into cobalt-phthalocyanines by application of heat, having a color ranging from yellow to brownred, that changes to orange-red upon reaction with primary amines, being soluble in concentrated hydrochloric acid and soluble in a strongly caustic alkaline solution containing methanol, said new cobalt compounds being obtainable by heating together a cobalt-salt, urea, a substance selected from the group consisting of phthalic anhydride, phthalimide and phthalonitrile, and catalytic quantities of ammonium molybdate, to temperatures up to from about 160 to about 170 C., stopping the heating when a yellow to brown-red solid is formed, and then recovering the yellow to brown-red solid from the reaction mixture.

2. The process of producing new complex compounds capable of being converted into cobalt phthalocyanines by application of heat, having a color ranging from yellow to brown-red, that changes to orange-red upon reaction with primary amines, being soluble in concentrated hydrochloric acid and soluble in a strongly caustic alkaline solution containing methanol, which process comprises heating together a cobalt-salt, urea, a substance selected from the group consisting of phthalic acids, phthalic anhydrides, phthalimides, and phthalonitriles suitable for the production of phthalocyanines, catalytic quantities of ammonium molybdate, and ammonium nitrate, to temperatures of about 185205 C., stopping the heating when a yellow to brown-red solid is formed and the simultane ously formed cobalt phthalocyanine has disappeared.

3. The process of producing complex cobalt compounds capable of being converted into cobalt phthalocyanine by application of heat, which process comprises heating together at about 140 C. in nitrobenzene phthalic anhydride, urea, cobalt chloride, catalytic quantities of ammoniummolybdate, and ammonium nitrate, gradually raising the temperature from 140 C. to 200205 C., and stopping the heating when the simultaneously formed cobalt phthalocyanine has disappeared.

4. The process of producing complex cobalt compounds, capable of being converted into cobalt phthalocyanine by application of heat, which process comprises heating together at about 170 C. in nitrobenzene phthalimide, urea, cobalt chloride, catalytic quantities of ammonium-molybdate, and ammonium nitrate, gradually raising the temperature from 170 to 200 C., and stopping the heating when the simultaneously formed cobalt phthalocyanine has disappeared.

5. The process of producing complex cobalt compounds, capable of being converted into cobalt phthalocyanine by application of heat, which process comprises heating together at about 170 C. in nitrobenzene phthalonitrile,

urea, cobalt chloride, catalytic quantities of ammonium molybdate, and ammonium nitrate, gradually raising the temperature from C. to 190 C., and stopping the heating when the simultaneously formed cobalt phthalocyanine has disappeared.

6. A composition of matter comprising a complex cobalt compound as defined in claim 1, an inert water-soluble organic solvent therefor, water, and a reducing agent for said complex cobalt compound.

7. A composition of matter comprising a complex cobait compound as defined in claim 1,' an inert watersoluble organic solvent therefor, water, a thickening substance, a strong alkaline agent of the group consisting of caustic alkalies, alkali metal carbonates and alkali metal sulfites, and a reducing agent for said complex cobalt compound.

8. A composition of matter comprising a complex cobalt compound as defined in claim 1, ethylene glycol, water, sodium hydroxide, a tragacanth thickening, and hydrazine sulfate.

9. A process for decorating textiles which comprises printing said textiles with a composition of matter comprising a complex cobalt compound as defined in claim 1, an inert water-soluble organic solvent therefor, water, a thickening substance and a reducing agent for said complex cobalt compound, and subjecting said textiles to an acid steam treatment.

10. A process for decorating textiles which comprises treating said textiles with a composition of matter comprising a complex cobalt compound as defined in claim 1, an inert Water-soluble organic solvent therefor, water and a reducing agent for said complex cobalt compound, and subjecting said textiles to a heat treatment.

11. A process for decorating textiles which comprises printing said textiles with a composition of matter com- 7 prising a complex cobalt compound as defined in claim 1,

an inert water-soluble organic solvent therefor, water, a thickening substance and a reducing agent for said complex cobalt compound, and subjecting said textiles to a heat treatment.

12. A process for decorating textiles which comprises printing said textiles with a composition of matter comprising a complex cobalt compound as defined in claim 1, an inert water-soluble organic solvent therefor, water, a thickening substance and a reducing agent for said complex cobalt compound, and subjecting said textiles to a steam treatment.

References Cited in the file of this patent UNITED STATES PATENTS 2,124,419 Heilbron July 19, 1938 2,276,918 Bicnert Mar. 17, 1942 2,469,663 Moser May 10, 1949 

1. NEW COMPLEX COBALT COMPOUNDS CONTAINING 6 MOLECULES OF PHTHALONITRILE PER ATOM OF COBALT, CAPABLE OF BEING CONVERTED INTO COBALT-PHTHALOCYANINES BY APPLICATION OF HEAT, HAVING A COLOR RANGING FROM YELLOW TO BROWNRED, THAT CHANGES TO ORANGE-RED UPON REACTION WITH PRIMARY AMINES, BEING SOLUBLE IN CONCENTRATED HDYROCHLORIC ACID AND SOLUBLE IN A STRONGLY CAUSTIC ALKALINE SOLUTION CONTAINING METHANOL, SAID NEW COBALT COMPOUNDS BEING OBTAINABLE BY HEATING TOGETHER A COBALT-SALT, UREA, A SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF PHTHALIC ANHYDRIDE, PHTHALIMIDE AND PHTHALONITRILE, AND CATALYTIC QUANTITIES OF AMMONIUM MOLYBDATE, TO TEMPERATURES UP TO FROM ABOUT 160* TO ABOUT 170* C., STOPPING THE HEATING WHEN A YELLOW TO BROWN-RED SOLID IS FORMED, AND THEN RECOVERING THE YELLOW TO BROWN-RED SOLID FROM THE REACTION MIXTURE.
 10. A PROCESS FOR DECORATING TEXTILES WHICH COMPRISES TREATING SAID TEXTILES WITH A COMPOSITION OF MATTER COMPRISING A COMPLEX COBALT COMPOUND AS DEFINED IN CLAIM 1, AN INERT WATER-SOLUBLE ORGANIC SOLVENT THEREFOR, WATER AND A REDUCING AGENT FOR SAID COMPLEX COBALT COMPOUND, AND SUBJECTING SAID TEXTILES TO A HEAT TREATMENT. 